Solar Eclipse: Northern Queensland

14th November 2012

On 14th November 2012, Australia will again experience the shadow of the moon as it passes between the Sun and the Earth. This event (second contact) will occur at 20:38UT on November 13th which translates to 6:38 am Australian Eastern Standard Time on 14th November due to the difference in the time zones.

The first point of contact for the shadow will be in the Northern Territory on the north east boarder of Kakadu National Park near Ubirr Rock. The path of the shadow will continue east across Arnhem Land, crossing the Gulf of Carpentaria then onto the Cape York peninsula near Wallaby Island. From here the shadow will progress south east crossing the eastern coast of Queensland 30 km north of Cairns.

Cairns and Port Douglas will provide some of the best viewing areas as they are populated tourist destinations providing ample accommodation and services. At the time of totality, the sun will have risen 14° above the horizon when it will last for two minutes.

As sunrise on the day will be approximately 5:35am, there is an hour available to find the best location for your observation point. there is the option to drive up or down the coast to find the best location north of Port Douglas, where their are open fields and places to stop with many other eclipse chasers. This require a bit of planning the day before as an early start in the dark will make it difficult to see what the cloud cover looks like. My suggestion is to find a comfortable spot on the balcony of your Resort room with a hot breakfast delivered to your room. All-in-all, coast observers might be better advised to sit and take whatever nature offers, as no matter what decision you make it will be just as good as any other on the day.

A total solar eclipse forms a rare opportunity to observe the corona (the outer layer of the Sun’s atmosphere). Normally this is not visible because the photosphere is much brighter than the corona. According to the point reached in the solar cycle, the corona may appear small and symmetric, or large and fuzzy. It is very hard to predict this prior to totality.

Phenomena associated with eclipses include shadow bands (also known as flying shadows), which are similar to shadows on the bottom of a swimming pool. They only occur just prior to and after totality, when a narrow solar crescent acts as an anisotropic light source

When the shrinking visible part of the photosphere becomes very small, Baily’s beads will occur. These are caused by the sunlight still being able to reach Earth through lunar valleys. Totality then begins with the diamond ring effect, the last bright flash of sunlight.

It is safe to observe the total phase of a solar eclipse directly only when the Sun’s photosphere is completely covered by the Moon, and not before or after totality. During this period the Sun is too dim to be seen through filters. The Sun’s faint corona will be visible, and the chromosphere, solar prominences, and possibly even a solar flare may be seen. At the end of totality, the same effects will occur in reverse order, and on the opposite side of the Moon.

Under normal conditions, the Sun is so bright that it is difficult to stare at it directly. However, during an eclipse, with so much of the Sun covered, it is easier and more tempting to stare at it. In fact however, looking at the Sun during an eclipse is as dangerous as looking at it outside an eclipse, except during the brief period of totality, when the Sun’s disk is completely covered (totality occurs only during a total eclipse and only very briefly; it does not occur during a partial or annular eclipse). Viewing the Sun’s disk through any kind of optical aid (binoculars, a telescope, or even an optical camera viewfinder) is extremely hazardous and can cause irreversible eye damage within a fraction of a second.

Looking directly at the photosphere of the Sun (the bright disk of the Sun itself), even for just a few seconds, can cause permanent damage to the retina of the eye, because of the intense visible and invisible radiation that the photosphere emits. This damage can result in impairment of vision, up to and including blindness. The retina has no sensitivity to pain, and the effects of retinal damage may not appear for hours, so there is no warning that injury is occurring.

Photographing an eclipse is possible with fairly common camera equipment. In order for the disk of the Sun/Moon to be easily visible, a fairly high magnification long focus lens is needed (at least 200 mm for a 35 mm camera), and for the disk to fill most of the frame, a longer lens is needed (over 500 mm). As with viewing the Sun directly, looking at it through the viewfinder of a camera can produce damage to the retina, so care is recommended.